Beans provides some helper methods that allow the basic operations of Bean-ness.
- *
- * @author John Keiser
- * @since JDK1.1
- * @version 1.1.0, 29 Jul 1998
- *
- */
-public class Beans {
- static boolean designTime = false;
- static boolean guiAvailable = true;
-
-
- /**
- * Once again, we have a java.beans class with only
- * static methods that can be instantiated. When
- * will the madness end? :)
- */
- public Beans() {
- }
-
- /**
- * Allows you to instantiate a Bean. This method takes
- * a ClassLoader from which to read the Bean and the
- * name of the Bean.- * - * The Bean name should be a dotted name, like a class. - * It can represent several things. Beans will search - * for the Bean using the name like this:
- *
null
- * to use the default ClassLoader.
- * @param beanName the name of the Bean.
- * @return the Bean.
- * @XXX
- */
- public static Object instantiate(ClassLoader cl, String beanName) throws IOException, ClassNotFoundException {
- Object bean;
-
- InputStream serStream;
- if(cl == null) {
- serStream = ClassLoader.getSystemResourceAsStream(beanName.replace('.','/')+".ser");
- } else {
- serStream = cl.getResourceAsStream(beanName.replace('.','/')+".ser");
- }
- if(serStream != null) {
- if(cl == null) {
- ObjectInputStream ois = new ObjectInputStream(serStream);
- bean = ois.readObject();
- } else {
- ClassLoaderObjectInputStream ois = new ClassLoaderObjectInputStream(serStream, cl);
- bean = ois.readObject();
- }
- } else if(cl == null) {
- Class beanClass = Class.forName(beanName);
- try {
- bean = beanClass.newInstance();
- } catch(IllegalAccessException E) {
- bean = null;
- } catch(InstantiationException E) {
- bean = null;
- }
- } else {
- Class beanClass = cl.loadClass(beanName);
- try {
- bean = beanClass.newInstance();
- } catch(IllegalAccessException E) {
- bean = null;
- } catch(InstantiationException E) {
- bean = null;
- }
- }
-
- if(bean instanceof Applet) {
- Applet a = (Applet)bean;
- //a.setAppletContext(???);
- //a.setStub(???);
- if(serStream == null) {
- a.init();
- }
- }
-
- return bean;
- }
-
- /**
- * Get the Bean as a different class type.
- * This should be used instead of casting to get a new
- * type view of a Bean, because in the future there may
- * be new types of Bean, even Beans spanning multiple
- * Objects.
- * @param bean the Bean to cast.
- * @param newClass the Class to cast it to.
- * @return the Bean as a new view, or if the operation
- * could not be performed, the Bean itself.
- */
- public static Object getInstanceOf(Object bean, Class newClass) {
- return bean;
- }
-
- /**
- * Determine whether the Bean can be cast to a different
- * class type.
- * This should be used instead of instanceof to determine
- * a Bean's castability, because in the future there may
- * be new types of Bean, even Beans spanning multiple
- * Objects.
- * @param bean the Bean to cast.
- * @param newClass the Class to cast it to.
- * @return whether the Bean can be cast to the class type
- * in question.
- */
- public static boolean isInstanceOf(Object bean, Class newBeanClass) {
- return newBeanClass.isInstance(bean);
- }
-
- /**
- * Find out whether the GUI is available to use.
- * Defaults to true.
- * @return whether the GUI is available to use.
- */
- public static boolean isGuiAvailable() {
- return guiAvailable;
- }
-
- /**
- * Find out whether it is design time. Design time means
- * we are in a RAD tool.
- * Defaults to false.
- * @return whether it is design time.
- */
- public static boolean isDesignTime() {
- return designTime;
- }
-
- /**
- * Set whether the GUI is available to use.
- * @param guiAvailable whether the GUI is available to use.
- */
- public static void setGuiAvailable(boolean guiAvailable) throws SecurityException {
- Beans.guiAvailable = guiAvailable;
- }
-
- /**
- * Set whether it is design time. Design time means we
- * are in a RAD tool.
- * @param designTime whether it is design time.
- */
- public static void setDesignTime(boolean designTime) throws SecurityException {
- Beans.designTime = designTime;
- }
-}